I have six 6-volt batteries, four 2ftx4ft solar panels, solar boost controller etc, and can give you the battery 101 if you want, no BS either, and your batteries will last 5 years, mine are from '01 or '02 and I never ran my gen untill a put a 37" HiDef widescreen in, now I might run it for 20 or 30 min at night if surfing the tube alot. 1) everytime you discharge your battery(ies) more than 50% you are shortening their lifespan, better to charge more often for a shorter period of time. Oh yeah, 50% is 12.25 volts +-, not 6 volts. 2)the best batteries for RVing (and usually least expensive) are "traction" batteries, golf cart/'fork lift. Heavy thick plates, just use the 6v in pairs wired series, then wire each pair parallelwith another pair. Just imagine a 6v as half a battery when hooking them together. AND ALWAYS REMOVE <NEGATIVE> 1ST AND ATTACH <NEGATIVE> LAST. Do the POSITIVE 1st and touch the wrench to grounded metal and the least you'll do is ugly up a wrench but if any battery "gas" present .... there's a 3,000ft ceiling for civilian use above Dumont, remember the Hindenburg? Hydrogen gas. Wear something for your eyes also, screw your clothes. Back to the 50%, get a cheap $5.00 digital multimeter from Harbor Freight put it on the next voltage above 12v dc and stick the probes in 1 of your seldom used 12v light bulb sockets and leave it on, no excuses, and don't cook the batteries dry, cycling the batteries alot (discharge-charge-discharge) makes them gas and use H2O, and use distilled water only. If you want to minimize the gen run time get a big auto charger from Walmart, Costco, etc , wherever, that can charge 40-50 amps continuous w/200 amp boost for under $100.00 (gen rebuilds are more maybe), I'll "bump" my batteries for 10-15 min with 230 amps +- then 60-70 awhile so I don't trip the thermal overload in the big charger. If you want to ask/see or even show/tell (about batteries, otherwise I ain't that kinda guy, hah) look for the tilted up solar panels on a 33ft pusher/22ft enclosed. Was by the DDR balloon area, going to look for a dust friendlier area I think (cough)